The present invention relates to a fuel supply apparatus of an engine and, more particularly, to an engine fuel supply apparatus provided with a fuel supply system for pressurizing and delivering fuel to be injected by an injector of a direct injection engine.
A fuel supply control apparatus of an engine in which abnormality of fuel pressure is detected without use of feedback control signals and a suitable care is taken is disclosed in JP A 9-119335. That is, the JP A 9-119335 discloses an engine fuel supply control apparatus which is characterized by comprising a high pressure fuel supply system for pressurizing and delivering fuel to be injected by an injector into a direct injection gasoline engine, an engine revelational speed sensor, an alarm, a fuel pressure sensor provided in the high pressure fuel supply system and sensing fuel pressure and a controller for energizing the alarm when the fuel pressure is above an upper limit value or below a lower limit value which are set corresponding to the engine revelational speed, and further it discloses an engine fuel supply control apparatus which is characterized in that an electromagnetic valve is provided in the high pressure fuel supply system and the controller controls the electromagnetic valve so as to close when the fuel pressure is below the lower limit value.
Only detection of the condition that the pressure in a high pressure pump abnormally increased or decreased may cause an erroneous judgement due to such an instant change in fuel pressure as does not really reach a region (hereunder, referred to as "accident region") in which the operation performance worsens.